telnet 설치
yum -y install telnet*
[root@server1 ~]# systemctl start telnet.socket
telnet을 시작해준다!
[root@server1 ~]# systemctl status telnet.socket
● telnet.socket - Telnet Server Activation Socket
Loaded: loaded (/usr/lib/systemd/system/telnet.socket; disabled; vendor preset: disabled)
Active: active (listening) since Tue 2021-07-13 09:35:46 KST; 8s ago
Docs: man:telnetd(8)
Listen: [::]:23 (Stream)
Accepted: 0; Connected: 0
[root@server1 ~]# firewall-cmd --add-port=23/tcp --permanent --zone=public
success
telnet의 port인 23번을 열어주고
[root@server1 ~]# firewall-cmd --reload
success
방화벽을 reload해준다
[root@server1 ~]# firewall-cmd --list-all
public (active)
target: default
icmp-block-inversion: no
interfaces: enp0s3 enp0s8
sources:
services: dhcpv6-client http ssh
ports: 80/tcp 23/tcp
재시작하고 방화벽 리스트를 확인하면 위와 같이 23/tcp를 확인할 수 있다!!
[root@server1 ~]# telnet localhost
telnet 접속
Trying ::1...
Connected to localhost.
Escape character is '^]'.
Kernel 3.10.0-1160.31.1.el7.x86_64 on an x86_64
server1 login: root
Password:
**기본적으로 root가 불가능
user3로 접속
telent 접속 성공!!
